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Electroconductive hydrogels are used in a wide range of biomedical applications, including electrodes for patient monitoring and electrotherapy, or as biosensors and electrochemical actuators. Approaches to design electroconductive hydrogels are often met with low biocompatibility and biodegradability, limiting their potential applications as biomaterials. In this study, composite hydrogels were prepared from a conducting polymer complex, poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) dispersed within a photo-crosslinkable naturally derived hydrogel, gelatin methacryloyl (GelMA). To determine the impact of PEDOT:PSS loading on physical and microstructural properties and cellular responses, the electrical and mechanical properties, electrical properties, and biocompatibility of hydrogels loaded with 0-0.3% (w/v) PEDOT:PSS were evaluated and compared to GelMA control. Our results indicated that the properties of the hydrogels, such as mechanics, degradation, and swelling, could be tuned by changing the concentration of PEDOT:PSS. In particular, the impedance of hydrogels decreased from 449.0 kOhm for control GelMA to 281.2 and 261.0 kOhm for hydrogels containing 0.1% (w/v) and 0.3% (w/v) PEDOT:PSS at 1 Hz frequency, respectively. In addition, an ex vivo experiment demonstrated that the threshold voltage to stimulate contraction in explanted abdominal tissue connected by the composite hydrogels decreased from 9.3 ± 1.2 V for GelMA to 6.7 ± 1.5 V and 4.0 ± 1.0 V for hydrogels containing 0.1% (w/v) and 0.3% (w/v) PEDOT:PSS, respectively. In vitro studies showed that composite hydrogels containing 0.1% (w/v) PEDOT:PSS supported the viability and spreading of C2C12 myoblasts, comparable to GelMA controls. These results indicate the potential of our composite hydrogel as an electroconductive biomaterial.

An efficient regioselective synthesis of trisubstituted 2(or 6)-arylaminopyrimidine-5-carbaldehydes is developed through an [S.sub.N]Ar reaction of 2,4,6-trichloropyrimidine-5-carbaldehyde with aniline, methylamine and alkoxide nucleophiles by using phase-transfer catalysis and [S.sub.N]Ar reaction conditions. The fused-bicyclic compounds are derivatized by using the Suzuki cross-coupling reaction to generate electronically and structurally unique G[logical and]C base precursors.

The synthesis and characterization of a chiral G^C motif that self-assembles into helical rosette nanotubes (RNTs) in methanol but undergoes mirror image supramolecular chirality inversion upon the addition of very small amounts of water is described. Studies shows that the mirror-image RNTs obtained, referred to as chiromers, result from thermodynamics (in water) and kinetic (in methanol) self-assembly processing involving two conformational isomers of the parent G^C motif.

The preparation of 25 beaded polystyrene-poly(ethylene glycol) graft copolymers from six spectroscopically active styrene monomers is described. Each of the 25 resins displayed a unique Raman and infrared vibrational fingerprint, which was converted into a 'spectroscopic barcode'.

A system wherein molecular chirality is expressed at the macromolecular level through two hierarchical processes is reported. At millimolar concentration, >=1mM, in methanol self-assembles into a racemic mixture of left (M)- and right (P)- handed helical rosette nanotubes.